The Warsaw Pact, formally the ‘Warsaw Treaty Of Friendship, Co‐operation and Mutual Assistance’ was formed in May 1955. The immediate reason given for its formation was the Paris Agreements amongst the Western powers that included West Germany in the North Atlantic Treaty Organization (NATO). To counterbalance this expansion of NATO, the Warsaw Pact set up a mutual defence organization, the Warsaw Treaty Organization (WTO), with a unified military command and headquarters in Moscow, which embraced the German Democratic Republic, as well as Albania, Bulgaria, Hungary, Poland, Romania, the Soviet Union, and the Czechoslovak Republic.
In practice the Warsaw Pact enabled the Soviet Union to station troops in these satellite states. In several satellites, these troops became a focus of protest during anti‐Soviet uprisings, as in Poland and Hungary in 1956. Hungary sought to leave the organization at the time, but failed. Similarly, Czechoslovakia failed to leave the Warsaw Pact in 1968, when the Soviet Union invoked the treaty against it to crush the Prague spring. Only Albania successfully withdrew from the pact in 1968, having developed closer links with China. The Warsaw Treaty Organization became defunct with the East European Revolutions in 1989, and the German Democratic Republic's withdrawal from it in 1990 was a largely symbolic act, which foreshadowed the Warsaw Pact's final dissolution in July 1991.